来自南非德纪的鱼
Robert W Gess1, Michael I Coates, Bruce S Rubidge
1Bernard Price Institute (Palaeontology), School for Geosciences, University of Witwatersrand, Johannesburg 2050, South Africa. robg@imaginet.co.za
Nature
|October 27, 2006
概括
一个新的化石,Priscomyzon riniensis,从纪晚期提供了证据,接近现代的无脊椎动物比以前想象的更早地进化. 这一发现凸显了灯的古老血统和非凡的持久性.
科学领域:
- 古生物学的古生物学
- 进化生物学 进化生物学
- 脊椎动物古生物学 脊椎动物古生物学
背景情况:
- 由于化石记录稀少,人们对Lamprey的进化历史知之甚少,只有少数已知的古生代和中生代的例子.
- 现有的化石表明,在解剖学上现代的鱼已经存在于白纪晚期,但早期的龙纪祖先仍然难以捉摸.
- 没有的脊椎动物 (agnathans) 代表了一个古老的血统,了解它们的多样化是脊椎动物进化的关键.
相关概念视频
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01:51Lampbrush Chromosomes
In 1882, Flemming observed lampbrush chromosomes (LBC) in salamander eggs. Later in 1892, Rückert observed LBCs in shark egg cells and coined the term "lampbrush chromosomes" because they looked like brushes used to clean kerosene lamps.
LBCs are made up of two pairs of conjugating homologous chromatids. Each chromatid consists of alternatively positioned regions of condensed-inactive chromatin and loosely placed-active side loops, which can be contracted and extended. The loops resemble the...
LBCs are made up of two pairs of conjugating homologous chromatids. Each chromatid consists of alternatively positioned regions of condensed-inactive chromatin and loosely placed-active side loops, which can be contracted and extended. The loops resemble the...
01:51Lampbrush Chromosomes
In 1882, Flemming observed lampbrush chromosomes (LBC) in salamander eggs. Later in 1892, Rückert observed LBCs in shark egg cells and coined the term "lampbrush chromosomes" because they looked like brushes used to clean kerosene lamps.
LBCs are made up of two pairs of conjugating homologous chromatids. Each chromatid consists of alternatively positioned regions of condensed-inactive chromatin and loosely placed-active side loops, which can be contracted and extended. The loops resemble the...
LBCs are made up of two pairs of conjugating homologous chromatids. Each chromatid consists of alternatively positioned regions of condensed-inactive chromatin and loosely placed-active side loops, which can be contracted and extended. The loops resemble the...